The ISAAC pipeline is entirely based on the eclipse library. You need to
download the library to compile the pipeline. Both packages can be found
at:

http://www.eso.org/eclipse/

Installation instructions are provided with the package and on the Web
site. After installation is complete, you should end up with a number of
executables in eclipse/bin. The main program you are looking for is
called isaacp, it contains the recipes for most of the ISAAC data
reduction modes, together with some basic documentation for the command
usage.